Barney walks at a velocity of 1.7 meters/second on an inclined plane, which has an angle of 18.5° with the ground. what is the horizontal component of barney’s velocity?

The velocities and the speed build a triangle, where the 1.7 m/s are the hypotenuse and the x-velocity and y-velocity are the other sides. 

So the x-velocity is: speed*cos(angle) 

now plug in 
x=1.7 m/s * cos(18.5)=1.597 m/s